Quick, reliable, and cost effective analytical and diagnostic methods are desirable.
PCT/SE03/00919 (Åmic AB) relates to a micro fluidic system comprising a substrate and provided on said substrate there is at least one flow path comprising a plurality of micro posts protruding upwards from said substrate, the spacing between the micro posts being small enough to induce a capillary action in a liquid sample applied, so as to force said liquid to move. There is disclosed that the device can comprise a denser zone which can act as a sieve preventing for instance cells to pass. There is also disclosed an embodiment with microstructures where the shape, size and/or center-to-center distance forms a gradient so that cells and the like can be delayed or separated.
PCT/SE2005/000429 (Åmic AB) shows a device and method for the separation of a component in a liquid sample prior to the detection of an analyte in said sample, wherein a sample is added to a receiving zone on a substrate, said substrate further optionally comprising a reaction zone, a transport or incubation zone connecting the receiving and reaction zone, respectively, forming a flow path on a substrate, wherein said substrate is a non-porous substrate, and at least part of said flow path consists of areas of projections substantially vertical to the surface of said substrate, and having a height, diameter and reciprocal spacing such, that lateral capillary flow of said liquid sample in said zone is achieved, and where means for separation are provided adjacent to the zone for receiving the sample. There is disclosed an embodiment where red blood cells are removed.
PCT/SE2005/000787 (Åmic AB) concerns a device for handling liquid samples, comprising a flow path with at least one zone for receiving the sample, and a transport or incubation zone, said zones connected by or comprising a zone having projections substantially vertical to its surface, said device provided with a sink with a capacity of receiving said liquid sample, said sink comprising a zone having projections substantially vertical to its surface, and said sink being adapted to respond to an external influence regulating its capacity to receive said liquid sample. It is disclosed that the device can be used when particulate matter such as cells is to be removed from the bulk of the sample. It is stated that red blood cells can be separated without significant rupture of the cells.
PCT/US2003/030965 (The General Hospital Corporation, and GPB Scientific LLC) discloses methods for separating cells from a sample. There is disclosed the separation of cells with different properties. The devices are closed devices with an input and output channel and a lid. The device comprises arrays of obstacles that are capable of binding a population of cells.
US 2007/0059718 A1 discloses methods for detecting and concentrating biohazard analytes such as bacteria, protozoa, viral pathogens, and toxins.
There is a need for a robust and reliable method for the analysis of circulating antibodies.